DWT Based Deflection Optimization in Deck Slab with Free Vibration Analysis

This review presents several types of deck slab technologies that have appeared over the last 20 years. The slab is a reinforced concrete slab that can reduce the amount (volume) of voided concrete. However, it has only been used in one way and must be supported by a beam and / or a fixed wall. The idea was to make a deck slab two-axis slab with the same function as a solid slab, but the weight was significantly reduced due to excessive concrete removal.

Instrumentation Results of New Manual for Assessing Safety Hardware Crash Tested Barriers for William P. Lane, Jr. Bridge

Two new bridge barriers were crash tested in accordance with AASHTO Manual for Assessing Safety Hardware (MASH) guidelines for future use on the William P. Lane Bridge over the Chesapeake Bay: (1) a combination barrier consisting of a reinforced concrete parapet with a top steel rail evaluated for Test Level 4 (TL-4); and (2) a combination barrier consisting of a steel parapet with a top steel rail evaluated for test levels TL-4 and TL-5. For the first test configuration, the reinforced concrete barrier was attached to a representative overhang deck slab using anchor rods. In the vicinity of the vehicle impact points, load cells were installed to measure forces in anchor bolts, and strain gauges were attached to reinforcing bars to resolve measured strain data into forces through the overhang deck slab. In the second test configuration, the steel barrier was supported by evenly spaced representative floorbeams using a bolted base plate connection. Strain gauges were attached to elements of the barrier at support locations adjacent to the vehicle impact point to evaluate force transfer through the barrier system into the base plate connections. Linear potentiometers were installed to measure lateral dynamic deflection of the barrier near the vehicle impact region. This paper presents the analysis results of the force, strain, and displacement data measured in the barrier and deck structural components during crash load testing.

Effect of Skew Angles on Longitudinal Girder and Deck Slab of Prestressed Concrete T Beam Girder Bridges

The present paper shows the effects of varying skew angles on pre-stressed concrete (PSC) bridges using finite elemental method. Studies are carried out on PSC bridge decks to understand the influence of skew angle and loading on behaviour of bridges. The results of skewed bridges are compared with straight bridges for IRC Class AA Tracked loading. Also, a comparative analysis of the response of skewed PSC Slab Bridge decks with that of equivalent straight bridge decks is made. The variation of maximum longitudinal bending moment (BM), maximum transverse moment, maximum torsional moment, and maximum longitudinal stresses deflection at obtuse corner, acute corner with skew angles are studied for bridge deck. It is found that Live load longitudinal bending moments decreases with an increase in skew angle, whereas a maximum transverse moment and maximum torsional moment increases with an increase in skew angle. The benefit of pre-stressing is reflected in considerable decrease in the longitudinal bending moment, transverse moment and longitudinal stresses. The models are analysed with the help of software CSI-Bridge V 20 Version. Keywords: Skew angle effect, Longitudinal moment, Transverse moment, CSI- Bridge software, Deck slab, Finite element method.

Bubble Deck Slab System: A Review on the Design and Performance

The conventional floor slab has few drawbacks of giving little structural support and posing a large amount of self-weight to a building. Therefore, bubble deck slab system is introduced to tackle these limitations. This paper aims to provide a comprehensive review of the bubble deck slab system on its design and performance. A systematic literature review was conducted in this paper based on the selected journal and articles through the database search engine. The findings will better understand the feasibility of the bubble deck slab system and its potential as a viable replacement for the conventional floor slabs.

Finite Element Analysis of I-Girder Bridge

In India railway bridge structures are widely designed with the method suggested by IRS – Concrete bridge code 1997.This Code of Practice applies to the use of plain, reinforced and prestressed concrete in railway bridge construction. It covers both in-situ construction and manufacture of precast units. The Code gives detailed specifications for materials and workmanship for concrete, reinforcement and prestressing tendons used in the construction of railway bridges. After defining the loads, forces and their combinations and requirements for the limit state design, particular recommendations are given for plain concrete, reinforced concrete and prestressed concrete bridge construction. The design of I-Girder bridge superstructure (deck slab and PSC I-beam) are done by calculating bending moments, shear forces, bending resistance in transverse direction, bending resistance in longitudinal direction, checking flexural cracking. The Design of PSC I-Girders is done for Bending moments and Shear forces by Dead Load, Super Imposed Dead Load (SIDL) and Live Loads (LL). The Shrinkage strain, Creep Strain and effect of Temperature rise and fall are also determined. The design is complete for Pre-stressing cables, un-tensioned reinforcements, End cross girder, Shear connectors. I-girder superstructures are the most commonly used superstructures at cross-over location in metro bridges in india, as it has the wide deck slab and it easily permits metro’s to change tracks. I-Girder superstructure construction is component wise construction unlike U-Girders. I-Girders are constructed in casting yard and its deck slab is cast in situ, parapets are also installed on later stage. Keywords: SIDL effects, Live Load effects, Derailment effect, with or without 15% future PT margin

Structural Design Issues On GFRP-Reinforced Concrete Bridge Barriers

In the era of bridge rehabilitation, glass fibre reinforced polymer (GFRP) bars are considered an alternative solution to steel reinforcement to eliminate steel corrosion. In this thesis, a new bridge barrier reinforcement layout was proposed incorporating GFRP bars with anchorage heads. However, it was observed that no design provisions or research data in the literature were found to design the anchorage at barrier-deck slab junction. As such, pullout tests were conducted on GFRP bars embedded in concrete slabs, to determine their pullout strength. Also, testing to-collapse of full-scale bridge barrier under static loading was conducted to determine its load carrying capacity. In addition, finite element analysis of the barrier wall and deck slab portion was performed in order to examine the level of accuracy of the specified factored applied moments due to vehicle impact at the barrier-deck junction. The experimental findings qualified the proposed GFRP-reinforced barrier detailing when subjected to simulated vehicle impact loading.

Investigation of the transverse and longitudinal moments at the transverse free end of deck slab cantilevers subjected to CHBDC truck loading

Clause 5.7.1.3 of the Canadian Highway Bridge Design Code (CHBDC) specifies an equation for the calculation of transverse moment intensity (My) in the deck slab cantilever due to truck loading in a slab-on-girder bridge system. Also, it states that the transverse moment intensity shall be assumed 2My for the locations within a distance equal to cantilever length of the transverse free end of the deck slab cantilever. However, CHBDC design values do not consider the effects of barrier length, variable thickness of the barrier wall and shape of the cantilever’s edge stiffening on the response. In addition, the longitudinal moment on the deck slab cantilever due to truck loading is as yet unavailable. Thus, a parametric study was conducted, using the finite element modelling, to investigate the effect of these key parameters in the transverse and longitudinal moments at the region of the transverse free edge of deck slab cantilever. Based on the data generated from this parametric study, imperial equations for the transverse and longitudinal moments at the transverse end of the deck slab cantilever were deduced.